菜鸟问题，关于类的destroy

只有垃圾回收到你new的对象时finalize方法才被调
试试这个：
public final class Finalize {
    public static int count = 0;
    private long come;
    private long go;
    public Finalize() {
        come = System.currentTimeMillis();
        count++;
        System.out.println("\r\nFinalize instance[" + hashCode() + "] borned.");
    }    protected final void finalize() throws Throwable {
        super.finalize();
        go = System.currentTimeMillis();
        System.out.println("\r\nFinalize instance[" + hashCode() + "] died.");
        System.out.println("\r\nLife time: " + (go - come)/1000 + " second(s).");
        Thread finalizer = Thread.currentThread();
        System.out.println("\r\nFinalizer Thread=[" + finalizer.getClass().getName() + "@" + Integer.toHexString(finalizer.hashCode()) + "].");
        count--;
        throw new Exception("Hihi.");
    }    public static void main(String[] args) {
        Thread t = new Thread(){
            public void run(){
                Thread tt = new Thread(){
                    public void run() {
                        Finalize f = new Finalize();
                    }
                };
                tt.start();
            }
        };
        t.start();
        long begin = System.currentTimeMillis();
        while(t.isAlive()) {
            try {
                Thread.currentThread().sleep(1000);
            } catch (Exception e) {
            }
            long end = System.currentTimeMillis();
            int time = (int)((end - begin) / 1000);
            System.out.print("\r" + time + " second(s) gone.");
        }
        while(Finalize.count > 0) {
            try {
                Thread.currentThread().sleep(1000);
            } catch (Exception e) {
            }
            long end = System.currentTimeMillis();
            int time = (int)((end - begin) / 1000);
            System.out.print("\r" + time + " second(s) gone.");
            if (time > 10) {
                System.gc();
                break;
            }
        }
    }
}
关于垃圾收集有很深的理论，什么样的对象才能拿去销毁有严格的定义
我只知道当线程结束时，线程的本地对象可以拿去销毁
上边例子可以验证